1. Field of the Invention
The present invention relates generally to seats for motor vehicles and, more specifically, to an occupant detection sensor assembly for a seat in a motor vehicle.
2. Description of the Related Art
It is known to provide seats for motor vehicles such as an automotive vehicle. Typically, a seat includes a generally horizontal seat cushion portion and a generally vertical seat back portion operatively connected to the seat cushion portion.
It is also known to provide a seat weight sensor for the seat cushion portion of the seat in a motor vehicle. For example, the seat weight sensor may be of a bladder type that requires a silicone-filled bladder be added to the seat cushion portion. The seat weight sensor measures changes in the pressure of the silicone-filled bladder and uses the output to infer the weight of an occupant sitting in the seat. In another example, a seat weight sensor uses a mat covered with force sensitive resistors installed inside a seat foam of the seat cushion portion to measure pressure distribution across the mat. The output of the seat weight sensor is used to infer occupant size. In still another example, a seat weight sensor uses a light source and a light detector inside the seat foam of the seat cushion portion to detect compression of the seat foam. Compressed seat foam generates a different light intensity than uncompressed seat foam. In the seat weight sensor, multiple light sources and detectors allow an approximation of weight distribution of the seat cushion portion to be calculated.
One disadvantage of the above seat weight sensors is that a bladder or matt is needed, which is undesired. Another disadvantage is that the seat weight sensors require components to be disposed inside the seat cushion portion, which is undesired. A further disadvantage is that the above seat weight sensors are used to measure the weight of an occupant and not for detecting an occupant in the seat.
Accordingly, the present invention is an occupant detection sensor assembly for a seat in a motor vehicle including a generally horizontal seat cushion portion operatively connected to vehicle structure and a generally upright seat back portion operatively connected to the seat cushion portion. The occupant detection sensor assembly includes a seat cushion disposed within the seat cushion portion of the seat having at least one channel therein. The occupant detection sensor assembly also includes at least one sensor connected to the seat cushion and communicating with the at least one channel and an electronic controller electrically connected to the at least one sensor for detecting an occupant seated on the seat cushion portion.
One advantage of the present invention is that an occupant detection sensor assembly is provided for a seat in a motor vehicle. Another advantage of the present invention is that the occupant detection sensor assembly detects or classifies an occupant in the seat, either their presence, their size, or their humanness. Yet another advantage of the present invention is that the occupant detection sensor assembly uses the seat foam itself as the medium for the sensor elements. Still another advantage of the present invention is that the occupant detection sensor assembly does not require components, other than sensors, to be disposed inside the seat cushion portion of the seat.
Other features and advantages of the present invention will be readily appreciated, as the same becomes better understood after reading the subsequent description when taken in conjunction with the accompanying drawings.